Cast concrete blocks are well known in the construction industry. They have a wide range of uses including constructing retaining and other walls, paving stones, edge restraints, base material, interlocking blocks, masonry products, and barriers. The interlocking blocks are advantageous for use since mortar is not needed to hold the blocks in place and strengthen the wall. The blocks are preferably cast as a dual block so that each cast block can be split into two individual blocks. This process increases the efficiency of the manufacturing process and gives an aesthetically desirable irregular or natural looking surface to the block face.
The manufacturing process includes at least one manufacturing step to cast the dual block and a separate manufacturing step to split the dual block into its individual blocks. U.S. Pat. No. 5,017,049 issuing May 21, 1991 to Sievert describes a masonry block and its construction. Sievert outlines a process where the block is formed in a mould, the block is cured, and then the block is split into its two component blocks. The block is split using a manual chisel and hammer or with a machine designed for this purpose. U.S. Pat. No. 5,598,679 issued Feb. 4, 1997 to Orton et al. describes a process for splitting a cast concrete block into three blocks. Again, the block is formed in a mould, cured and then split. The cured block is split into its component blocks by advancing splitting knives along the cutting grooves.
These known processes require a separate step in the manufacturing process, specialized machinery and result in increased handling of the blocks. This requirement results in additional costs to the manufacturer. There therefore is a need for a process for casting concrete blocks where dual blocks can be split into individual blocks without the need for additional machinery and an additional manufacturing step. There also is a need for a process for casting concrete blocks which is more economical and which reduces the handling of the blocks.